function CheckSilverlightInstalled() {
    var isSilverlightInstalled = false;
    try {
        try {
            var slControl = new ActiveXObject('AgControl.AgControl')//IE
            isSilverlightInstalled = true;
        }
        catch(e) {
            if (navigator.plugins["Silverlight Plug-In"]) //FF&Safari
            {
                isSilverlightInstalled = true;
            }
        }
    }
    catch(e) {
    }
    return isSilverlightInstalled;
}